xref: /freebsd/sys/libkern/inet_pton.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996,1999 by Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/param.h>
19 #include <sys/socket.h>
20 #include <sys/systm.h>
21 
22 #include <netinet/in.h>
23 
24 /*%
25  * WARNING: Don't even consider trying to compile this on a system where
26  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
27  */
28 
29 static int	inet_pton4(const char *src, u_char *dst);
30 static int	inet_pton6(const char *src, u_char *dst);
31 
32 /* int
33  * inet_pton(af, src, dst)
34  *	convert from presentation format (which usually means ASCII printable)
35  *	to network format (which is usually some kind of binary format).
36  * return:
37  *	1 if the address was valid for the specified address family
38  *	0 if the address wasn't valid (`dst' is untouched in this case)
39  *	-1 if some other error occurred (`dst' is untouched in this case, too)
40  * author:
41  *	Paul Vixie, 1996.
42  */
43 int
44 inet_pton(int af, const char *src, void *dst)
45 {
46 	switch (af) {
47 	case AF_INET:
48 		return (inet_pton4(src, dst));
49 	case AF_INET6:
50 		return (inet_pton6(src, dst));
51 	default:
52 		return (-1);
53 	}
54 	/* NOTREACHED */
55 }
56 
57 /* int
58  * inet_pton4(src, dst)
59  *	like inet_aton() but without all the hexadecimal and shorthand.
60  * return:
61  *	1 if `src' is a valid dotted quad, else 0.
62  * notice:
63  *	does not touch `dst' unless it's returning 1.
64  * author:
65  *	Paul Vixie, 1996.
66  */
67 static int
68 inet_pton4(const char *src, u_char *dst)
69 {
70 	static const char digits[] = "0123456789";
71 	int saw_digit, octets, ch;
72 #define NS_INADDRSZ	4
73 	u_char tmp[NS_INADDRSZ], *tp;
74 
75 	saw_digit = 0;
76 	octets = 0;
77 	*(tp = tmp) = 0;
78 	while ((ch = *src++) != '\0') {
79 		const char *pch;
80 
81 		if ((pch = strchr(digits, ch)) != NULL) {
82 			u_int new = *tp * 10 + (pch - digits);
83 
84 			if (saw_digit && *tp == 0)
85 				return (0);
86 			if (new > 255)
87 				return (0);
88 			*tp = new;
89 			if (!saw_digit) {
90 				if (++octets > 4)
91 					return (0);
92 				saw_digit = 1;
93 			}
94 		} else if (ch == '.' && saw_digit) {
95 			if (octets == 4)
96 				return (0);
97 			*++tp = 0;
98 			saw_digit = 0;
99 		} else
100 			return (0);
101 	}
102 	if (octets < 4)
103 		return (0);
104 	memcpy(dst, tmp, NS_INADDRSZ);
105 	return (1);
106 }
107 
108 /* int
109  * inet_pton6(src, dst)
110  *	convert presentation level address to network order binary form.
111  * return:
112  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
113  * notice:
114  *	(1) does not touch `dst' unless it's returning 1.
115  *	(2) :: in a full address is silently ignored.
116  * credit:
117  *	inspired by Mark Andrews.
118  * author:
119  *	Paul Vixie, 1996.
120  */
121 static int
122 inet_pton6(const char *src, u_char *dst)
123 {
124 	static const char xdigits_l[] = "0123456789abcdef",
125 			  xdigits_u[] = "0123456789ABCDEF";
126 #define NS_IN6ADDRSZ	16
127 #define NS_INT16SZ	2
128 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
129 	const char *xdigits, *curtok;
130 	int ch, seen_xdigits;
131 	u_int val;
132 
133 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
134 	endp = tp + NS_IN6ADDRSZ;
135 	colonp = NULL;
136 	/* Leading :: requires some special handling. */
137 	if (*src == ':')
138 		if (*++src != ':')
139 			return (0);
140 	curtok = src;
141 	seen_xdigits = 0;
142 	val = 0;
143 	while ((ch = *src++) != '\0') {
144 		const char *pch;
145 
146 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
147 			pch = strchr((xdigits = xdigits_u), ch);
148 		if (pch != NULL) {
149 			val <<= 4;
150 			val |= (pch - xdigits);
151 			if (++seen_xdigits > 4)
152 				return (0);
153 			continue;
154 		}
155 		if (ch == ':') {
156 			curtok = src;
157 			if (!seen_xdigits) {
158 				if (colonp)
159 					return (0);
160 				colonp = tp;
161 				continue;
162 			} else if (*src == '\0') {
163 				return (0);
164 			}
165 			if (tp + NS_INT16SZ > endp)
166 				return (0);
167 			*tp++ = (u_char) (val >> 8) & 0xff;
168 			*tp++ = (u_char) val & 0xff;
169 			seen_xdigits = 0;
170 			val = 0;
171 			continue;
172 		}
173 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
174 		    inet_pton4(curtok, tp) > 0) {
175 			tp += NS_INADDRSZ;
176 			seen_xdigits = 0;
177 			break;	/*%< '\\0' was seen by inet_pton4(). */
178 		}
179 		return (0);
180 	}
181 	if (seen_xdigits) {
182 		if (tp + NS_INT16SZ > endp)
183 			return (0);
184 		*tp++ = (u_char) (val >> 8) & 0xff;
185 		*tp++ = (u_char) val & 0xff;
186 	}
187 	if (colonp != NULL) {
188 		/*
189 		 * Since some memmove()'s erroneously fail to handle
190 		 * overlapping regions, we'll do the shift by hand.
191 		 */
192 		const int n = tp - colonp;
193 		int i;
194 
195 		if (tp == endp)
196 			return (0);
197 		for (i = 1; i <= n; i++) {
198 			endp[- i] = colonp[n - i];
199 			colonp[n - i] = 0;
200 		}
201 		tp = endp;
202 	}
203 	if (tp != endp)
204 		return (0);
205 	memcpy(dst, tmp, NS_IN6ADDRSZ);
206 	return (1);
207 }
208 
209 /*! \file */
210